Changing Landscape: Today's Astronomy Picture of the Day shows changes on the surface of Saturn's moon Titan. What's going on down there?
"Damn,” said the geologist who had been handling the sled with such effortless skill. “I was afraid of that. Something tells me I’m never going to catch a worm on the run.”
Only a few kilometers away, coming out of the mist that always enveloped the flanks of Mount Shackelton, was a thin white line, like a piece of rope laid across the landscape. It stretched away downhill until it disappeared over the horizon, and the driver swung the sled around to follow its track. But Duncan already knew that they were too late to achieve their main objective; they were much too close to World’s End. Minutes later, they were there, and the sled came to a stop at a respectful distance.
(Arthur C. Clarke, Imperial Earth)